Apparatus, method, and system for event and backup lighting

ABSTRACT

An apparatus, system, and method for solid state lighting is envisioned which, according to aspects of the invention, provides primary event and/or utility lighting during normal power conditions, and which, during periods of interrupted power, provides uninterrupted event lighting for a desired duration, provides a gradual transition from event lighting levels to utility lighting levels, and provides a gradual transition from utility lighting levels to emergency lighting levels.

I. CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 of a provisionalapplication Ser. No. 61/425,139 filed Dec. 20, 2010, and whichapplication is hereby incorporated by reference in its entirety.

II. BACKGROUND OF INVENTION

The present invention generally relates to the field of large arealighting, such as lighting for sports events. More specifically, thepresent invention relates to the response of lighting systems to poweroutages which could occur at sports events or other public gatherings.

Lighting Needs for Sports Venues

Sports venues and other large areas requiring lighting usually requirevarying levels of lighting for use at different times. The most light isrequired during active use of the facility for sports or activities.Less light may be required before the event when people are arriving andafter the event when people are still present. A much lower level oflight is required for emergency exit during power outages, and possiblyfor maintenance and security purposes when the venue is not occupied bylarge numbers of people.

The above three types of lighting that might be used at sports venueswill be considered herein under the following definitions: “Eventlighting” is lighting provided primarily on and near the sports field,track, etc. for the benefit of the participants, to allow the spectatorsto see clearly, for television lighting, etc. “Utility lighting” islighting that is provided for spectators to be able to see and moveabout within the location, exit the stands, etc. It may be provided inpart by “event lighting” and may be provided in part by separatefixtures or lighting systems. “Emergency lighting” is any lights orsystem of lighting that provides a minimum level of lighting to thelocation to allow safe exit of the location, or which may be useful formaintenance, security, or continued emergency use.

Adequate “event lighting” for participants in sports events is necessaryto allow safe and effective conduct of a sport or activity. Forinstance, it is well known that the ability to perceive moving objectsis related to several factors, including velocity, size, contrast, andcolor. If an object is moving very fast, is relatively small, is of lowcontrast with its surroundings or is a color similar to its background,it can be difficult to perceive. Because of this, sports such asbaseball and automobile racing rely on a high level of event lighting toprovide adequate lighting. Other sports or activities can also require ahigh level of event lighting.

“Utility lighting” for spectator safety and convenience is related toevent lighting. A relatively low level of utility lighting in comparisonto the required event lighting can be (by itself) adequate, sincemovement within the facility does not require the same degree of visualacuity, particularly since spectators do not normally have directinteraction with high speed activities such as throwing, batting,competitive driving, etc. However, when high levels of event lightingare present, the eye can be accustomed to the relatively high level ofutility lighting. If the event lighting level is suddenly anddramatically reduced, spectators will be left without the ability ofmove easily within the facility until their eyes readjust to thediminished light level, and will typically experience some degree ofunease with their surroundings due to the sudden and drastic change.

“Emergency lighting” for a typical sports venue is typically consideredto be sufficient lighting to proceed safely to exits but is notconsidered adequate as utility lighting. Public facilities which useartificial lighting are normally required to provide emergency light atan illumination level and for a duration which is adequate forevacuation of the facility. A typical required duration is 90 minutes.However, the safe evacuation of a facility is not the only foreseeableuse of emergency backup lighting. In the event of various types ofdisruptions or disasters, a venue such as a sports stadium might be usedfor emergency shelter, storage, emergency operations staging, etc. Thusthe ability to provide extended lighting, even at a very low level,could be beneficial.

For sports venues, in the event of a power interruption, “required”emergency lighting may not be satisfactory or ideal, since emergencylighting levels do not provide adequate event or utility lighting. Manysports venues could benefit from having a system that providessubstantially the same light level in the event of a power failure tohelp reduce the risk of low visibility of high-speed objects, or foraesthetic, convenience, or other reasons. For example, baseballs can bethrown or batted at a very high velocity—on the order of 100 feet persecond or more. Loss of light, even for a very short time, would make itdifficult to follow the movement of a ball in the air, which couldresult in a player or spectator being hit by the ball. Similarly, racecars travel at a very high rate of speed. If lighting were to beinterrupted or be significantly diminished during an automobile race,drivers could lose control of their vehicles.

Types of Backup Systems

There are various existing types of backup systems. The UninterruptiblePower Supply (UPS) type of backup system (sometimes known as a “doubleconversion” or “online” system) provides instant full power to alighting system in the event of a power interruption. It takes AC gridpower and converts it to DC power. The DC power is used to chargestorage batteries. The same DC power is fed to an inverter whichconverts DC to AC power to power a lighting system. In the even of powerinterruption, DC power from the storage batteries flows withoutinterruption to the DC-to-AC inverter, which is able to maintain full ACvoltage output to the lighting system without any loss of voltage orinterruption or modification of the AC sine wave output. Considerationsfor use of this type of system include the fact that by itself, itmaintains the same event lighting for a specified period, typically 90minutes. This may completely exhaust the batteries, making it impossibleto provide any extended lighting period. Since the very high levels ofevent lighting are only needed for a short time in order to completepotentially risky activities, this may not be an efficient use oflimited backup power. Reducing lighting levels in order to increaseduration of emergency lighting would require additional controls ormanual switching of lights by knowledgeable personnel. Or, multiplebackup systems would be required to provide power to different lightingsystems having different output levels. No provision for adjustment oflight levels is provided with a typical UPS type system. A completebackup system using a UPS type system may therefore be too expensive orcomplicated, or may not provide sufficient duration of backup, extremelow level lighting, or other desired benefits.

An “emergency light” type backup system typically provides low levelillumination at a minimum level and duration required for evacuation ofa venue. The lighting fixtures are provided for walking paths and exits,and do not provide the ability to complete or safely stop potentiallyrisky sports activities.

Variations or combinations of these systems may be installed, whichincreases the cost and complexity of the backup system. A UPS systemcould be installed which allows event lighting to be continued for agiven duration, while an emergency system provides extended lighting ata lower level. Still, gradual dimming would be difficult or impossiblewithout extensive additional equipment and cost.

Desired Lighting Solutions for Sports Venues

It would therefore be desirable for sports venues, in the event of powerinterruption, to provide a high level of event and utility lighting, aswell as emergency lighting that is at or above the minimum requiredlevel. It would be beneficial for these lighting levels to be providedfor a longer duration and/or at a lower cost than is commonly obtained.

Specifically, there is a need for backup event lighting using existinglighting fixtures which in the event of a power failure providesuninterrupted event lighting that is of functionally identical intensityand quality to the primary lighting, for a duration sufficient to safelycomplete or terminate potentially risky activities. For a baseball game,this could allow the thrown or batted ball to be safely stopped,possibly for the play to be completed, helping to reduce the chance ofplayers getting hit by an airborne baseball or a substantial disruptionof the game or activity for a relatively short duration. Or for anautomobile race, this would allow vehicles to slow down safely under acaution flag. Further, there is a need for the ability to provide agradual transition from event lighting levels to lower levels, therebyallowing sufficient time for eye adjustment to lower lighting levels andreducing potential panic or discomfort which might arise due to suddenreduction in lighting levels.

Likewise, there is need for backup utility lighting, using existingevent or utility lighting fixtures, that exceeds minimum standards foremergency lighting and that provides benefits in terms of duration andquality in comparison to existing standards for emergency lighting. Thiswould lead to less inconvenience and less spectator discomfort ordissatisfaction. Further, there is a need for the ability to provide agradual transition from utility lighting levels to lower emergencylighting levels, thereby allowing sufficient time for eye adjustment tolower lighting levels and reducing potential panic or discomfort whichmight arise due to sudden reduction in lighting levels.

Likewise, there is need for emergency lighting using existing event orutility lighting fixtures that exceeds minimum standards for emergencylighting and that provides benefits in terms of duration and quality incomparison to existing standards for emergency lighting. Further, thereis a need for the ability to provide a gradual transition from emergencylighting levels to lower lighting levels which might still be useful inthe event of extended power interruption, thereby allowing sufficienttime for eye adjustment to even lower lighting levels and reducingpotential panic or discomfort which might arise due to sudden reductionin lighting levels or complete loss of lighting. Thus the ability toprovide lower light levels down to 10%, or even as small as on the orderof 2% or less of original event or utility lighting levels could bebeneficial and desirable.

Thus, improvements in the art are desirable.

III. SUMMARY OF THE INVENTION

It is therefore a principle object, feature, advantage, or aspect of thepresent invention to improve over the state of the art or addressproblems, issues, or deficiencies in the art.

An apparatus, system, and method for solid state lighting is envisionedwhich, according to aspects of the invention, provides primary eventand/or utility lighting during normal power conditions, and which,during periods of interrupted power, provides uninterrupted eventlighting for a desired duration, provides a gradual transition fromevent lighting levels to utility lighting levels, and provides a gradualtransition from utility lighting levels to emergency lighting levels.

Further, an apparatus, system, and method is envisioned according toaspects of the invention which provides a gradual transition fromemergency lighting levels to lower lighting levels which may be verylow, and which may be shut down according to a schedule or timeline, orwhich may remain illuminated as long as even minimal backup power isavailable.

Further, an apparatus, system, and method for solid state lighting isenvisioned which according to aspects of the invention may work intandem with a separate emergency type backup lighting system in order tomaximize the quality and duration of backup lighting, and which mayprovide low level lighting for emergency or other use which may beunrelated to sports event lighting.

Further, an apparatus, system, and method for solid state lighting isenvisioned which according to aspects of the invention may work withexisting lighting control and reporting systems that may be on oroff-site, to provide information about the state of the lighting systemor to allow remote control of the lighting system.

IV. BRIEF SUMMARY OF THE DRAWINGS

FIG. 1 shows an enlarged scale schematic representation of a typical LEDlight that could be used in embodiments of the invention.

FIGS. 2-3 show a greatly reduced-in-scale elevation of a typical LEDlighting installation according to aspects of the invention.

FIG. 4 illustrates logical operation of an embodiment according toaspects of the invention.

FIGS. 5-8 illustrate the functional components of embodiments accordingto aspects of the invention.

FIG. 9 is a flow chart of a method according to aspects of theinvention.

V. DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS A. Figures

From time to time in this description, reference will be made toappended figures. Reference numbers or letters will be used to indicatecertain parts or locations in the figures. The same reference numbers orletters will indicate the same or similar parts or locations throughoutthe figures unless otherwise indicated.

B. Overview

An apparatus, system, and method for solid state lighting is envisionedwhich according to aspects of the invention provides primary eventand/or utility lighting during normal power conditions, and which,during periods of interrupted power or under other desiredcircumstances, using existing event or utility lighting fixtures and/ornewly provided lighting fixtures, provides one or more of the following:

-   -   a. provides uninterrupted event lighting that is or is        substantially of functionally identical intensity and quality to        the primary lighting for a duration sufficient to safely        complete or terminate hazardous activities;    -   b. provides a gradual transition from event lighting levels to        utility lighting levels;    -   c. provides uninterrupted utility lighting, that exceeds minimum        standards for emergency lighting and that provides benefits in        terms of duration or quality in comparison to existing standards        for emergency lighting;    -   d. provides a gradual transition from utility lighting levels to        lower emergency lighting levels, thereby allowing sufficient        time for eye adjustment to lower lighting levels;    -   e. provides uninterrupted emergency lighting using existing        event or utility lighting fixtures that exceeds minimum        standards for emergency lighting and that provides extended        duration and/or enhanced quality in comparison to existing        standards for emergency lighting;    -   f. provides a gradual transition from emergency lighting levels        to lower lighting levels which might still be useful in the        event of extended power interruption, thereby allowing        sufficient time for eye adjustment to even lower lighting;    -   g. provides lower light levels even as small as on the order of        2% or less of original event or utility lighting levels for an        extended duration;    -   h. provides one or more shutdown options, which may include        allowing lighting to continue at reduced levels as long as        sustainable from the backup power supply;    -   i. provides a warning signal such as flashing the lights for a        short period of time indicating a change in lighting mode (e.g.        changing from event lighting to utility lighting or from utility        lighting to emergency lighting).

An apparatus, system, and method for solid state lighting is envisionedwhich according to aspects of the invention may work in tandem with aseparate emergency type backup lighting system in order to maximize thequality and duration of backup lighting without requiring long durationuse of full power backup event lighting.

An apparatus, system, and method for solid state lighting is envisionedwhich according to aspects of the invention may provide low levellighting for emergency or other use which may be unrelated to sportsevent lighting.

An apparatus, system, and method for solid state lighting is envisionedwhich according to aspects of the invention may work with existinglighting control and reporting systems that may be on or off-site, toprovide information about the state of the lighting system or to allowremote control of the lighting system.

The embodiments according to aspects of the invention present somedifferences from existing systems. For example, existing systemstypically do not allow using the same light fixtures for both eventlighting, utility lighting, and emergency lighting. Thus for existingsystems, if a power backup system is applied only to emergency lightingcomponents, high speed activities may become risky in the event of apower interruption. On the other hand, if a power backup system isapplied to event lighting, either available duration of backup lightingis much shorter, or energy storage required is much greater. Thus forany given storage capacity, the envisioned embodiments may provide muchgreater duration backup lighting.

Some benefits of the embodiments include:

-   -   a. providing uninterrupted event light in the event of power        interruption thereby reducing the risk of injury from a ball in        the air, cars traveling at high speed, etc.    -   b. providing utility lighting for an extended time period,        allowing greater spectator comfort and confidence than provided        by much dimmer emergency lighting.    -   c. providing emergency lighting at a higher intensity for an        extended time period, allowing greater safety and usability of a        location under extended adverse circumstances.    -   d. providing gradual dimming between lighting levels, thereby        reducing the level of discomfort or anxiety due to sudden        lighting changes, and reducing effects of temporary visual        impairment due to the time required for the eye to adapt to        lower light levels.    -   e. allowing reporting and offsite control of the lighting        system.

Some additional benefits of the preceding embodiments include:

-   -   a. doesn't require a full UPS system.    -   b. can be integrated with a driver system.    -   c. is not limited to a typical emergency lighting configuration.    -   d. provides a high range of difference between brightest event        lighting and dimmest functional emergency lighting, allowing        management of backup power according to circumstances. This        means that normal event lighting, backup event lighting, backup        utility lighting, emergency lighting, and long duration        emergency lighting may be provided from the same lighting        fixtures.    -   e. allows dimming with existing drivers or solid state switching        without requiring emergency backup systems separate from event        or utility lighting systems.

C. First Exemplary Embodiment: Lighting System with Self-ContainedBackup System

An apparatus, system, and method for solid state lighting is envisionedwhich according to aspects of the invention provides primary eventand/or utility lighting for sports or other large area lighting needsduring normal power conditions, and which, during periods of interruptedpower or under other desired circumstances, using existing event orutility lighting fixtures, provides functionally uninterrupted eventlighting, which is transitioned to successively lower levels.

Functionally, the lighting system would operated at a given power levelfor normal event lighting using grid power. In the event of powerinterruption, “backup event lighting” would be maintained withoutinterruption at or substantially at the original level and quality for apre-determined time period. The pre-determined time could be on theorder of 10 seconds to 1 minute, or much longer. Power would be suppliedby batteries, ‘long life batteries, capacitors, super-capacitors, orother source of emergency power.

After a specified period of time, the light levels would be lowered overa period of some seconds or minutes to a predetermined level. Lightinglevel could be lowered gradually or step-wise over a successive periodof minutes or hours as appropriate in order to maximize visibility andlighting utility while considering possible future lighting needs.

Reduction of lighting level could also be accomplished by selectivelyturning off individual LEDs or some portion of lighting fixture LEDarrays, using addressable solid state switching within power drivers ordistribution systems or using conventional switching methods.

FIGS. 1-2 illustrate the apparatus according the first exemplaryembodiment. One or more LED lights 10, FIG. 1, are typically mounted aspart of an array 20, FIG. 2 on a pole 30 or other structure, as part ofa system of lighting for a sports venue or other location. Power isinput (at e.g. 35) from AC (grid) power. Transformer/rectifier 40converts AC to DC current at voltages suitable to supply driver 50 andbattery 70. In the event of a power interruption, battery 70 supplies DCpower to driver 50. (As embodied, these components may be supplied asseparate components and connected by appropriate wiring 15, or combinedin some fashion, or may be included within one common case or even onone common board such as controller 60.) One example of a controller isa programmable microprocessor.

The output from driver 50 to the lighting array 20 is typically a‘current source’ type, which provides a specified current through one ormore LEDs in a string. It can also use synchronous or asynchronous pulsemodulation, linear dimming, or other means which are well known in theart to control power supplied to LEDs. The controller 60 is programmedto control these functions.

Block diagram 401 in FIG. 4 illustrates logical operation of theenvisioned first embodiment. Event lighting ON signal 400 from e.g. amanual operator, automatic controller, etc., and other control inputssuch as optional remote interface input 435, optional manual controlinput 440, optional variable programming 420, UPS back-up mode signaling410 and Main Power and System Status signals 430, are collected atControl Inputs node 450. Main Power and System Status signal 430 is alsooptionally provided to Remote Interface 435. Based on control inputs450, the system selects lighting mode (see node 460); either normalevent lighting 480, backup mode 470, or optional modes 490. Optionalmodes could include operating the lights at a low level lighting forextended duration such as for emergency lighting purposes unrelated toevent lighting, or tying the operational control back to a central or alocal control and monitoring system. Another optional mode would bemanual control of lighting level as desired. Another optional mode wouldbe remote control of lighting level as desired. Many other optionalmodes could be designed and selected. When backup mode 470 is selected,the appropriate backup mode is selected at node 500. Normally, backupevent lighting 510 would continue for a predetermined time, on the orderof 10 seconds to 1 minute. Lights would then dim to backup activitylighting level 520 for a longer period of time, on the order of 15minutes to 2 hours. Lights would be further dimmed to emergency lightinglevel 530 for a longer period which could be on the order of severalhours. Finally, lights could be dimmed to extended emergency lightinglevel 540 which could be on the order of several hours to one or moredays. The extended emergency lighting level could be on the order of 10%down to 2% or less of primary event or utility lighting levels. Finally,lights could be turned OFF 550, either because of complete discharge ofpower storage, ineffectiveness of lighting below a certain level, orbecause there was no further need for lighting.

The power storage medium could be commercially-available batteries,capacitors, or other technology capable of providing DC or AC current.Batteries would normally provide the longest backup time. Capacitorswould generally provide much shorter backup time, but might have muchlower needs and costs for maintenance, and might not have the same shelflife issue as batteries.

As an example, assume an operational program that causes the lights tooperate for 10 seconds on full brightness, with a ramp-down to 10%brightness within two minutes, and an additional period of operation at10% brightness for total of two hours. Power required from a batterybackup system may be roughly calculated by multiplying the power usageper second times the number of seconds, then converting to watt hoursdivided by battery voltage to give amp hours required from a backupbattery system. Therefore power required for a single fixture having 50LEDs operating at 1 watt each would be

For the initial period: 50 watts×10 seconds=500 watt seconds.

For the ramp down period the average usage for two minutes={[50watts−(50 watts×10%)]/2×120 seconds+[50 watts×10%×120 seconds]}=[2700watt seconds+600 watt seconds]=3300 watt-seconds.

For the two hour period, [50 watts×10%×3600 seconds/hour×(2 hours−2minutes and 10 seconds)]=35350 watt seconds.

For the total time period, 500+3300+35350 watt seconds=39,150 wattseconds.

The total power required for a two hour, two minute, and 10 secondemergency operation is 39,800 watt seconds. At 3600 watt seconds perwatt hour, this is just under 11 watt hours. Rounding up to 12 watthours to allow for some system inefficiency, and dividing by 12 voltsavailable from a typical storage battery, this is 1 ampere-hour. Incomparison, a typical marine/RV deep cycle battery such as the StowawayBattery ST27DC180, available commercially (e.g. from retail storesoperated by Tractor Supply Company, 200 Powell Place, Brentwood, Tenn.37027) is rated at 105 ampere hours. This means that a single 12 voltdeep cycle battery could supply 100 such fixtures for a two houremergency operation. Additionally, at 10% power, the fixture wouldrequire 5 watt hours, which from a 12 volt battery equates to 0.417ampere hours, or about ½ ampere hour per hour of operation. This wouldallow over 200 hours of operation of the single fixture from that samebattery.

Block diagram 501 of FIG. 5 illustrates the functional components ofthis embodiment. A manual input such as a switch 605 provides manualinput signal 610 to controller 620. Controller 620 monitors the AC powersource (see 670). Driver 690 provides current 700 to drive LED lights710. The AC power source (line power) 660 provides AC current 665 totransformer/rectifier 650. Transformer/rectifier 650 provides DCcharging output 640 to power storage 630. Transformer/rectifier 650 alsoprovides DC operating current 680 to driver 690.

Block diagram 1001 of FIG. 9 illustrates the programming with regard topower monitoring and ‘power out’ operation for controller 620, FIG. 5.Controllers described in other embodiments would operate similarly.Control input 1020, FIG. 9 (=manual input 605, FIG. 5) is evaluated bycontroller, 1010. Based on the signal from the control input, thecontroller 1930 sends a signal between 0 and 10 volts to the driver 1035(=driver 690, FIG. 5). The controller periodically checks, 1040, for apower drop-out signal 1050 (=670, FIG. 5) and evaluates, 1060 if powerhas dropped out. If ‘no,’ 1062, operation is normal, 1095 and thecontrol cycle begins again at 1010. If ‘yes,’ 1061, the ‘power out’protocol 1070 is implemented. This protocol can be as desired, and couldbe variable with inputs from the operator, or could be programmed intothe controller memory. For example, the program could be designed tomaintain existing light levels for 10 seconds, gradually drop lightlevel to 10% over a period of 2 minutes, and operated at 10% until poweris restored or system power is depleted. Once the ‘power out’ protocol1070 is implemented, the controller checks 1080, and evaluates, 1085, ifpower is restored. If ‘no,’ 1087, the controller maintains 1090 powerout protocol 1070. If ‘yes’ 1086, controller returns to normal operation1095.

Note that the components used in the embodiments are well known in theindustry, and may be selected from many models for size, capacity,price, performance, reliability, etc. Some exemplary components thatwould be suitable are listed below. For example, controller 620, FIG. 5,which could be adapted through software or minor hardware modificationto include the functions described herein, has been described in detailin U.S. Ser. No. 13/248,859 filed Sep. 29, 2011 and incorporated byreference herein. An exemplary transformer/rectifier (also applicable to720 and 650, FIG. 6) is the BPI 400 Industrial Power Supply Moduleavailable from BIAS Power, 1368 Busch Parkway Buffalo Grove, Ill. 60089.LED driver 690 can be the 100W TRC-100DS available from ‘ThomasResearch, 11548 Smith Drive, Huntley, Ill. 60142. The battery (‘powerstorage’ 630) could be any of thousands of commercial models, includingthe previously described ST27DC180. LED lights 710 could be the unitsdescribed in U.S. Ser. No. 12/751,519 filed Mar. 31, 2010, and publishedas U.S. 2010/0195326 (now U.S. Pat. No. 8,449,144) and incorporated byreference herein, or could be any other fixture using multiple LEDs.

D. Second Exemplary Embodiment: Lighting System Integrated withCommercial UPS

A second apparatus, system, and method for solid state lighting isenvisioned which according to aspects of the invention provides primaryevent and/or utility lighting for sports or other large area lightingneeds during normal power conditions, and which, during periods ofinterrupted power or under other desired circumstances, using existingevent or utility lighting fixtures, provides functionally uninterruptedevent lighting, which is transitioned to successively lower levels.

Functionally, the lighting system would operated at a given power levelfor normal event lighting using grid power which is provided through acommercially available UPS. In the event of power interruption to theUPS, it would continue to provide the equivalent of grid power to thelighting system. However, the lighting system would initiate a backupresponse strategy similar to the previous embodiment which would tend tomaximize the backup power available from the UPS while still providing“backup event lighting” followed by backup utility lighting andemergency lighting. Optionally, power from the UPS could be supplementedby batteries, capacitors, or other source of emergency power inaccordance with the previous embodiment.

In the event of power interruption, a signal from the UPS or from aseparate power monitoring function or circuit would signal the lightingsystem to begin a backup response in accordance with the previousembodiment.

FIG. 3 illustrates the apparatus according the second embodiment. ACpower 35 is input to the UPS 80. UPS 80 supplies power totransformer/rectifier 40 which supplies DC current to driver 50. In theevent of a power interruption, UPS 80 continues to supply power totransformer/rectifier 40. Output from driver 50 continues to supply LEDarray 20 but is modified according to instructions from controller 60.

A commercial UPS as utilized in this embodiment includes battery storageand UPS circuitry which provides double conversion protection. Blockdiagram 401 of FIG. 4 illustrates logical operation of the envisionedsecond embodiment which is functionally similar to the first embodiment;however in the case of the second embodiment, power to the LED driver isprovided through the UPS, so event lighting 480 is provided by the gridthrough the UPS.

The block diagram 601 of FIG. 6 illustrates the functional components ofthis embodiment. A manual input such as a switch 605 is connected to andsends signal 610 to controller 620. Controller 620 monitors the AC powersource 660 (via power source monitor signal 670) and the status of thecommercial UPS 780 (via UPS monitor signal 790). Driver 690 provides avariable voltage or current 700 to drive LED lights 710. The AC powersource (line power) 660 provides AC current to UPS transformer/rectifier720. Transformer/rectifier 720 provides DC charging output 730 to powerstorage 740. Power storage 740 can then provide 760 DC power output.Transformer/rectifier 720 also provides DC operating current 750 to UPSinverter 770. UPS inverter 770 provides AC power 775 totransformer/rectifier 650.

While a commercial UPS typically provides AC current emulating gridpower, UPS units are available which provide DC output instead. This DCpower could be provided directly to the LED driver circuit. In thiscase, an AC transformer/rectifier 650 would not be needed in the LEDdriver circuit.

Benefits of this embodiment could include the ability to retrofit to anexisting UPS backup system, while enhancing emergency lightingmanagement capabilities. This could allow the ability to move from fullbackup event lighting to backup utility lighting to emergency lightingusing same physical lighting components. This could furthersignificantly extend duration of emergency lighting during a powerinterruption, eliminate or reduce need for separate emergency lights,and provide extra functionality for extended use of facilities duringextended power interruption.

Some exemplary components that would be suitable in this embodiment, inaddition to the components listed previously herein, are listed below.An examplary UPS inverter 770, FIG. 6, is the UltraLITE Model ELUCentralized Emergency Lighting Inverter, available from Controlled PowerCompany, 1955 Stephenson Highway, Troy, Mich. 48083.

E. Third Exemplary Embodiment

A third optional embodiment is shown in the block diagram 701 of FIG. 7.During normal operation, grid power 800 is provided to LED driver 880through AC switching relay 870. The LED driver 880 provides current tooperate LED fixture 895. LED controller 890 provides a variable 0-10 VDCcontrol signal to LED driver 880. External control inputs 885 may beprovided to vary LED brightness by signaling the LED controller 890.

If a power outage occurs, power switch 870 switches the AC power sourcefor LED driver 880 from grid power 800 to inverter 860. Drop outdetection function 820 monitors grid power at AC switch 870. If a poweroutage occurs, the drop out detection function signals LED controller890 to operated under a ‘power down’ mode which begins to dim lightsaccording to a pre-programmed schedule. Power detection function 820also signals battery switch 850 to connect DC power from battery 830 toinverter 860.

Inverter 860 is kept ‘on’ and ‘idle’ by power from DC power supply 840.This allows the inverter to provide AC power to AC switch 870 morequickly than if it were powered down and required a cold start frombattery power in the event of power outage.

Battery 830 is kept charged by battery charger 810 which is powered byAC power grid 800.

Some exemplary components that would be suitable in this embodiment,have been listed previously. An exemplary switching relay 870, FIG. 7,is the KRP-14AN-120-ND available from Tyco Electronics Corporation, 1050Westlakes Drive, Berwyn, Pa. 19312.

F. Fourth Exemplary Embodiment

A fourth optional embodiment is shown in block diagram 801 of FIG. 8. InFIG. 8, fixture 995 receives power from inverter 960. Inverter 960receives power from switching electronics unit 970, which receives powerfrom driver 980, if AC power 900 is uninterrupted, or from battery 930if AC power is interrupted. AC power 900 is provided to charger 910which charges battery 930.

Some exemplary components that would be suitable in this embodiment havebeen listed previously.

G. Options and Alternatives

As can be appreciated by those skilled in the art, the invention cantake many forms and embodiments. Variations obvious to those skilled inthe art will be included herein. Additional options and alternativesaccording to aspects of the invention are many and varied. Someoptions/alternatives include:

-   -   a. using both batteries and capacitors to provide the benefits        of both types of technology, or other power supplies such as        emergency generators, including very low powered generators in        conjunction with intentionally dimmed output.    -   b. LED/solid state lights could be simultaneously dimmed, or        individual groups of LEDs could be shut off, or both strategies        could be followed, allowing control of different light levels at        different locations in a playing field, stadium, etc.    -   c. An alarm function or ‘flash’ circuit could be provided.        Different colors or different flash intervals could be used to        indicate system status. If different colored LEDs are used, they        could be part of a visual alarm system—e.g. flashing red LEDs        only intermittently. This alarm or flash circuit could be used        e.g. to indicate that a power outage was in effect, that lights        would be dimming, or that lights were nearly out of power.        Different colors or flash sequences, etc. might be used to        indicate different conditions.    -   d. In the event of a power interruption, the backup circuit        could startup immediately without warning, or lights could        “flicker” or “flash” (i.e. either drop visual lighting levels,        increase lighting levels, or both).    -   e. The system could be used in conjunction with a light sensor        in the fixture that measures ambient light. Light output could        be coordinated with available light in order to maintain at        least a minimum light level, while providing for maximum battery        life under emergency conditions. In this instance, a desired        total lumen value could be specified, and the control program        would compare available light to light output in order to        provide the desired light level.    -   f. An additional method to conserve battery life could be        implement a control program having a ‘special mode’ on the        driver that provides a pulse-width modulated (PWM) output at        around 100 hz, which would be above the flicker point, but would        have a duty cycle low enough to conserve battery life.    -   g. The system could report status (such as e.g. ‘event’,        ‘utility’, or ‘emergency’ lighting modes, as well as fault        detection and battery status variables) back to a centralized        control system. An example of a centralized control system would        be CONTROL LINK™ by Musco Corporation, which uses the wireless        internet to communicate from a central server to widely        distributed controllers associated with lighting systems in        different locations across the country, or even the world.        Details of such a system can be found at U.S. Pat. Nos.        6,681,110 and 7,778,635, which are incorporated by reference        herein.    -   h. Battery charging could be done by using solar chargers,        possibly saving significant cost vs. some types of battery        charging systems.    -   i. The individual components listed as parts of embodiments        according to aspects of the invention are well known in the        industry. Many have been previously listed herein. Any        components not specifically listed would be available as a        standard or custom product from many different suppliers and        might be located through an internet search or a component        supplier such as Digi-Key Corporation, 701 Brooks Avenue South,        Thief River Falls, Minn. 56701; McMaster-Carr, 200 New Canton        Way, Robbinsville, N.J. 08691; Allied Electronics, Inc., 7151        Jack Newell Blvd. S., Fort Worth, Tex. 76118, or many other        similar suppliers.

The foregoing description is by way of example and not limitation. It isneither exclusive or inclusive of all forms and embodiments theinvention can take. Variations obvious to those skilled in the art areincluded in the invention, which is defined by the appended claims.

What is claimed is:
 1. A method of large area lighting for a lightingapplication comprising: a. providing illumination from anelectrically-powered lighting system at: i. event lighting level; or ii.utility lighting level; b. upon a power interruption to the lightingsystem providing: i. uninterrupted event or utility lighting for arelatively short duration; and ii. a gradual transition from event orutility lighting to an emergency lighting level; iii. wherein thegradual transition comprises either a stepless or a step-wise change inlighting levels.
 2. The method of claim 1 further comprising a gradualtransition from emergency lighting level to a lower than emergencylighting level.
 3. The method of claim 2 further comprising a gradualtransition from the lower than emergency lighting level to shut downaccording to a schedule or timeline.
 4. The method of claim 1 whereinthe large area lighting comprises sports, stadium, arena, or other largevenues for the public.
 5. The method of claim 1 wherein the lightingsystem comprises: a. high intensity discharge light sources; and/or b.solid state light sources.
 6. The method of claim 1 wherein powerinterruption is automatically sensed.
 7. The method of claim 1 whereinthe relatively short duration is determined by one or more factorsincluding but not limited to: a. available power supply.
 8. The methodof claim 7 wherein the available power supply comprises a battery supplyand a DC to AC converter.
 9. The method of claim 1 wherein the gradualtransition is determined by one or more factors including but notlimited to: a. available power supply.
 10. The method of claim 1 furthercomprising a gradual transition between event lighting level to utilitylighting level before gradual transition to emergency lighting level ifthe lighting system is at event lighting level at the time of powerinterruption.
 11. A system for providing large area lighting for alighting application comprising: a. a plurality of high intensity lightfixtures adapted to provide event or utility lighting levels; b. a powerand control circuit to the fixtures in communication with an ACelectrical power source; c. a sensor for sensing interruption of the ACelectrical power source to the power and control circuit; d. a back upsource of electrical power; e. a sub-system including a controllerconfigured to; i. automatically change-over to the back up source ofelectrical power upon the sensing of interruption of the AC electricalpower source; ii. automatically control operation of the power andcontrol circuit of the fixtures to provide:
 1. uninterrupted event orutility lighting for a relatively short duration;
 2. a gradualtransition from event or utility lighting to a wherein the gradualtransition from event or utility to a lower level comprises graduallyreducing lighting levels followed by shut down of the light fixtures andautomatic turn on of separate emergency light level lighting fixtures.12. The system of claim 11 wherein the back up source comprises: a. aback up battery system; b. an emergency generator system.
 13. The systemof claim 11 wherein the wherein the gradual transition from event orutility to a lower level comprises control of the said lighting fixturesto emergency light level.
 14. The system of claim 11 further comprisingdiscretionary control the lighting fixtures for a gradual transitionbetween any of event, utility, emergency, or shut down light levels forreasons apart from sensing of power interruption.
 15. A method ofautomatically controlling a wide or large area lighting system for suchevents as sports contests, automobile racing, or public showscomprising: a. providing sufficient electrical power from the publicelectrical power grid to provide illumination at: i. event lightinglevel; or ii. utility lighting level; b. upon sensing an interruption ofgrid power to the lighting system providing from an alternative powersource: i. uninterrupted event or utility lighting for a relativelyshort duration; and ii. a gradual transition from event or utilitylighting to an emergency iii. wherein status of the lighting system iscommunicated to a remote monitoring system and the remote monitoringsystem provides control signals to the lighting system to influence orcontrol the transition from event or utility lighting to an emergencylighting level or to lighting levels as desired.
 16. The method of claim15 wherein the relatively short duration is determined by capacity ofthe alternative power source and nature of the contest, racing, or show.17. The method of claim 16 wherein the nature of the contest, racing, orshow comprises a reasonable length of time: a. to complete a play in asporting contest; b. to slow a racing car down to caution or yellow flagtrack condition; or c. for human eyes to adapt to a difference betweenevent lighting level and a lower level.